His mission was to aggressively expose the Romney/Ryan platform as full of falsehoods, and get out a series of key talking points: the “47 percent,” the saving of General Motors, the refusal of congressional Republicans to work with President Obama, and their slavish devotion to an extreme ideology on taxes, abortion, and Grover Norquist. Biden managed to get those points out, in one instance, during a single answer. Asked by the moderator, veteran ABC reporter Martha Raddatz, what the Obama administration would do to get unemployment under 6 percent, and when, the vice president reeled off an exhaustive (and exhausting) bill of particulars:

… I don’t know how long it will take. We can and we will get it under 6 percent. Let’s look at — let’s take a look at the facts. Let’s look at where we were when we came to office. The economy was in free fall. We had — the great recession hit; 9 million people lost their job; $1.7 — $1.6 trillion in wealth lost in equity in your homes, in retirement accounts for the middle class.

We knew we had to act for the middle class. We immediately went out and rescued General Motors. We went ahead and made sure that we cut taxes for the middle class. And in addition to that, when that — when that occurred, what did Romney do? Romney said, “No, let Detroit go bankrupt.” We moved in and helped people refinance their homes. Governor Romney said, “No, let foreclosures hit the bottom.”

But it shouldn’t be surprising for a guy who says 47 percent of the American people are unwilling to take responsibility for their own lives. My friend recently in a speech in Washington said “30 percent of the American people are takers.”

These people are my mom and dad — the people I grew up with, my neighbors. They pay more effective tax than Governor Romney pays in his federal income tax. They are elderly people who in fact are living off of Social Security. They are veterans and people fighting in Afghanistan right now who are, quote, “not paying any tax.”

I’ve had it up to here with this notion that 47 percent — it’s about time they take some responsibility here. And instead of signing pledges to Grover Norquist not to ask the wealthiest among us to contribute to bring back the middle class, they should be signing a pledge saying to the middle class we’re going to level the playing field; we’re going to give you a fair shot again; we are going to not repeat the mistakes we made in the past by having a different set of rules for Wall Street and Main Street, making sure that we continue to hemorrhage these tax cuts for the super wealthy.

And with that, he became an instant hero of the Democratic base.

Biden used his age and experience to his advantage, making the youthful-looking 42-year-old congressman appear much younger, and far from the star who once threatened to overshadow Mitt Romney. When Biden repeatedly referred to the prime minister of Israel as “Bibi,” and flaunted his foreign policy acumen, it stood in stark contrast to Ryan’s faltering knowledge of Afghanistan.

The vice president was dismissive of his young opponent, turning the term “my friend” into the prelude to an insult. He constantly brought the focus back to Ryan’s record in Congress. (Raddatz apparently ignored an apparent request from the Romney campaign that Ryan be addressed as “Mr. Ryan” rather than “congressman,” which one can only assume is due to Congress’ abysmal approval ratings.) He brought up the “47 percent” remarks made by Romney at a private fundraiser in May, no fewer than five times, and literally laughed when Ryan attempted to make a case for Romney’s tax plan, or the ticket’s plans for Medicare. And Ryan was forced to own both the Medicare voucher plan, and his desire to partially privatize Social Security.

Republicans are crying foul on Biden’s derisive laughter and interruptions, accusing Biden of being “disrespectful” to his opponent. There’s a case to be made that Biden was over the top during the first 30 minutes of the debate — though the base, again, loved it. But more importantly, those who last week (including much of the media) praised Romney’s constant interruptions and diminution of the moderator, PBS’ Jim Lehrer, are in an awkward place criticizing Biden for doing the same to Ryan. It’s also hard to imagine an Obama surrogate explaining Ryan’s debate performance as caused by his being “lazy,” as Romney surrogate John Sununu described Obama after last week’s presidential debate, with nary a walk-back from the campaign.

During a particularly pointed riff, Biden looked into the camera and asked the television audience to “trust your instincts” on whether Americans should trust Medicare to the party that passed it, or to the party that wants to privatize it, along with Social Security. And Biden decimated Ryan’s argument on taxes, in part because Ryan refused to provide specifics on how his and Romney’s tax cuts for the wealthy would be paid for, and in part by the deployment of a classic Biden closing line:

BIDEN: Now, there’s not enough — the reason why the AEI study, the American Enterprise Institute study, the Tax Policy Center study, the reason they all say it’s going — taxes go up on the middle class, the only way you can find $5 trillion in loopholes is cut the mortgage deduction for middle-class people, cut the health care deduction, middle-class people, take away their ability to get a tax break to send their kids to college. That’s why they arrive at it.

RADDATZ: Is he wrong about that?

RYAN: He is wrong about that. They’re…

BIDEN: How’s that?

RYAN: You can — you can cut tax rates by 20 percent and still preserve these important preferences for middle-class taxpayers…

Far from being Kennedyesque, Ryan at times during the debate seemed like an earnest young college student who dutifully memorized his lessons for oral exams, only to find out he would be debating his teacher. When Biden reminded him of the two letters the congressman had mailed the vice president asking for stimulus funds so that jobs could be created in his Wisconsin district, all Ryan could do was grimace — and drink a lot of water. A lot of water.